In many manufacturing operations, particularly with respect to plastic fabrication, it is not uncommon for some of the materials that are employed in the operation to be shipped to the manufacturing facility in heavy containers, e.g. drums, barrels, gaylords, bulk truck, rail cars, silo, day bins, flat bottom bins, or other utility bins which may or may not have a sloped bottom or flat bottom. Drums are typically fiber drums that are typically cylindrical, but can be other shapes as well, and usually hold between 200 to 250 lbs of material. Barrels can be the traditional barrels such as those made with staves of wood or other suitable material including metal and plastic. Gaylords are typically cubic corrugated containers, usually with a 1000 pound weight limit and are often made of cardboard material, however, they are not limited to this material and may be comprised of plastic as well.
Any of these containers may be delivered by any number of means to the manufacturing facility and are stored until they are required for use in the manufacturing process. The containers can be stored anywhere on the manufacturing site as desired and can be transported from the storage location by any suitable means such as by a fork lift, a conveyor belt, etc. Once the contents of the container are needed, the forklift or other device will remove the container from the storage site and transport it to the location where it is needed. There, the container is either emptied all at once or only portions are removed from time to time on an as needed basis. However, usually these containers are too heavy to be lifted by a person and a mechanical means is necessary to remove the contents.
For some particulate material or bulk resin contained in the container, such as plastic pellets or powders and the like, a vacuum system or similar conveyance means can be used to remove the material from the container and transport it through piping or tubing, or other similar means often used in conveying lines, to wherever it is needed for manufacturing purposes. It is typical to use a vacuum loader to empty these containers. A vacuum loader is comprised of, at least, a lance or wand which is directly or indirectly coupled to a vacuum source. The lance or wand is placed in the container and is either manually forced to the bottom by an operator or placed on top of the contents of the container and allowed to suction its way to the bottom. However, the wand or lance is relatively stationary. Thus, it only has the option of suctioning the contents of the container that are immediately around the wand or lance. To this end, without operator assistance to reposition the lance or wand, the vacuum loader is inefficient to remove all of the particulate material and may leave as much as half the contents within the container. Accordingly, an employee must constantly monitor the wand and manually adjust it to ensure all of the material is removed from the container. This is very costly in terms of labor and lost production.
One possible solution to this problem is addressed in European Patent No. EP 1 199 266, disclosing a device and method for evacuating bulk material. Specifically, EP 1 199 266 teaches a suction apparatus that may be lowered into a sack or sack-like container. The suction apparatus, once inserted into the sack, rests on top of the bulk resin contained therein and sinks as the resin is evacuated. The container is coupled to a lifting apparatus wherein the lifting apparatus is adapted to raise and lower the sack along the vertical axis. As the sack is raised, the diameter of the sack is reduced, thereby, forcing the resin toward the center of the container and facilitating the ability of the suction apparatus to reach substantially all of the resin. In this configuration, however, the container must be one that is easily manipulated. In other words, it is limited to a sack or sack-like container and does not provide a solution for evacuating resin from more rigid container types, e.g. drums, barrels, gaylords, bulk truck, rail cars, silo, day bins, flat bottom bins, or other utility bins.
Thus, there remains a need in the art for an apparatus and method for removing particulate material, e.g. plastic pellets, powder, and the like, from a relatively rigid storage container without requiring operator intervention or manipulation of the container. Moreover, there is a need in the art for a vacuum loader to improve the quantity of particulate matter removed from a container while reducing lost labor due to the inefficiencies of the equipment.
The present invention addresses the foregoing needs.